A radiation detecting device, such as a flat panel X-ray detector (FDXD), is widely used in a medical industry, a veterinary industry or non-destructive testing industry. The radiation detecting device is generally composed of a radiation detecting panel for converting radiation signals like the X-ray into electric signals, a driving unit for driving the panel, a signal detecting unit for detecting signal output from the radiation detecting panel.
In particular, the radiation detecting panel includes an upper substrate and a lower substrate opposite to each other, a scintillating layer inserted between the two substrates, a photoelectric device and a thin film transistor. The scintillating layer converts the X-rays into the visible rays, the photoelectric device converts these visible rays into currents, the thin film transistor plays a role of a switch for controlling the output of the currents. Thus, the radiation detecting panel can output the electric signals after converting the X-ray into the electric signals.